Conventionally, a motor vehicle indicator light such as an indicator light for giving signals to other traffic, of the kind in which the light source consists of light emitting diodes, the diodes are carried on a substrate which is for example a printed circuit, and a regulating circuit is provided which mainly consists of a power resistor, the regulating circuit being mounted away from the light emitting diodes. One example of this kind of light is described in U.S. Pat. No. 5,325,271.
It has recently been proposed to provide a structure for an indicator light using light emitting diodes which enables the remote regulating circuit to be omitted. That proposed solution consists of incorporating in the network of light emitting diodes crosswise resistors, each of which is associated with one of the diodes and connected in series with the latter. One such circuit is shown in FIG. 1 of the accompanying drawings. In FIG. 1 the resistors are indicated by the reference numeral 1, while the diodes are indicated by the reference numeral 2.
Such a structure eliminates problems related to the wires that connect the substrate carrying the light emitting diodes with the regulating circuit consisting of the power resistor. However, that arrangement is still not fully satisfactory. In particular, the proximity of the resistors and the light emitting diodes gives rise to excessive heating of the diodes. This in turn results in a substantial reduction in their performance, giving a loss of emission in the order of 40%.